/******************************************************************************

                              Online C++ Compiler.
               Code, Compile, Run and Debug C++ program online.
Write your code in this editor and press "Run" button to compile and execute it.

*******************************************************************************/

#include <iostream>

using namespace std;

int cmmdc(int a, int b) {
    while (b != 0) {
        int r = a % b;
        a = b;
        b = r;
    }
    return a;
}

int solve(int n) {
    int result = 0;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= n; j++) {
            if (cmmdc(i, j) == 1) {
                result++;
            }
        }
    }
    return result;
}

int main()
{
    bool test = false;
    if (test == true) {
        if (solve(3) != 7) cout << "wrong answer for 3";
        if (solve(4) != 11) cout << "wrong answer for 4";
        if (solve(5) != 19) cout << "wrong answer for 5";
        if (solve(10) != 63) cout << "wrong answer for 10";
    } else {
        int n;
        cin >> n;
        
        cout << solve(n) << endl;
    }

    return 0;
}